The basic idea of content delivery network (CDN) is to avoid bottlenecks and links that can affect the speed and stability of data transmission in the internet as much as possible, to transmit data with higher speed and higher stability. By arranging node servers at different locations in the network to form a smart virtual network based on the existing internet, CDN may redirect a user's request, in real-time, to a closest server node based on comprehensive information such as network traffic, connection at each node, load condition, distance to the user, and response time. The goal is facilitating the user to obtain desired content from a closest server, resolving internet congestion, and increasing the response speed when a user accesses a website. In the recent years, the development of smart phones has greatly improved users' internet browsing experience, the wide spread usage of smart phones enables mobile web browsing to become an extension of PC web browsing, and a large portion of traditional internet users gradually merge to mobile phone network. Mobile network has increasingly evolved to an important entrance and a main platform for innovation of internet operation, and has become an important information hub for information communication for new social media, e-commerce, and various new applications. Mobile internet has great market potential and is releasing the potential in high speed.
Conventional CDN is often applied in fixed networks, and has inferior optimization effect on mobile network. The reasons include:
1. A fixed network has simple environment, and is often connected to a user through ADSL dial-up or fiber access; while a mobile network has complex environment, 2G, 2.5G, 3G, 4G, and WiFi, and each standard includes many types based on different carriers, for example 3G includes WCDMA, CDMA2000, TD-SCDMA, etc. Each standard and type has its own special features, and the methods for optimization are quite different.
2. A fixed network has high speed, small fluctuations, and fairly consistent user experience, so that conventional CDN manufacturers and clients often emphasize on throughput and usability rather than speed. A mobile network has lower speed, higher fluctuations, is susceptible to network malfunctioning, and its user experience is significantly lower than fixed networks. Thus, the transmission speed of the mobile network is desired to be significantly increased.
In addition, when conventional CDN is applied in the mobile network, the following shortcomings exist:
1. The traffic scheduling, based on the domain name system (DNS), has fairly low accuracy, and is susceptible to DNS pollution and traffic hijacking. Also, when a services node is malfunctioning, the service node may be blocked through DNS. The wait time for effective network access is overly long, causing the speed to access network in the mobile network applied with CDN to be undesirably low.
2. Often conventional CDN only supports a few mainstream protocols such as HTTP, and many applications supporting proprietary protocols do not support CDN service.
3. Express protocols such as HTTP have low security level. When a phone terminal is using a public WiFi hotspot, a higher security level is desired.
In view of the low accuracy in traffic scheduling in a mobile network applied with CDN, no effective solution has been provided so far.